I have been having trouble finding an answer for this in the Star documantation, so thought someone might be able to answer here.

In the postprocessing section of the star guide it is possible to plot pressure, static pressure, thermo. pressure and total pressure. What does the 'pressure' value represent if it is not static, total or thermo pressure?

Again, for temperature, it is possible to plot temperature and total temperature. Does the 'temperature' value mean static temperature or something else?

And lastly, some plots change significantly between the 'cell' and 'cell and wall bound (smooth)' plot options. Exactly what are the differences between these plot options?

I don't know anything about the "thermo" aspects, but can tell you the following:

GETV (or GETC) PRESSURE generally loads static pressure. You will find that pressure and static pressure only differ if you have bouyancy switched on, in which case, I think pressure will include the rho g h term, whereas static pressure will not.

Total pressure (PTOT) converts the local velocity to a pressure term and adds that to the static pressure; this means it is something like stagnation pressure.

Total temperature is the same - GETC T will give you static temperature, while TTOT will give you the "stagnation" temperature.

The last question is easy. If you load data using the 'cell' option (command line equivalent is GETC) you get the data actually recorded in each cell. No interpolation is done, and each cell is completely coloured according to its value.

'cell and wall bound (smooth)' (command line equivalent is GETV) loads in the cell data as above, then interpolates it onto the vertices, taking the boundary conditions into account, and gives you smooth contours.

In between these is GETC and CAVE ALL (sorry, don't know the GUI equivalent) which does the interpolation and smoothing, but does NOT take boundary conditions into account.